Adjustable windage tray and method for operation of the adjustable windage tray

ABSTRACT

Methods and systems are provided for adjusting a flow profile of a windage tray. In one example, a method for operation an engine system is provided that includes operating an engine to perform combustion, determining an engine speed, and adjusting a flow profile of a plurality of deflectors in a windage tray positioned in a crankcase based on the engine speed.

FIELD

The present description relates generally to an engine with an enginesystem including an adjustable windage tray and a method for operationof said engine system.

BACKGROUND/SUMMARY

Engines have utilized windage trays positioned in crankcases to modifyflow dynamics in the crankcase. The use of windage trays is particularlyprevalent in high performance engines, due to the propensity of highperformance engines to be operated at high speeds for extended periods.However, the necessity of the windage tray varies based on engineoperating conditions. During lower engine speeds the turbulence in thecrankcase may not cause the oil aeration issues that are so prevalent atthe high engine speeds. However, as the engine speed increases, themomentum of the crankcase flowfield and oil leakage via componentbearings, perturb and impinge with high velocity on the free surface ofthe oil within the oil reservoir. Aeration is an inherent consequence ofthe oil interacting with the highly turbulent flowfield within thecrankcase. A more quiescent oil free surface is one of the design goalsof previous windage trays. However, during lower engine speeds oilaeration considerably decreases and may not pose a significant problem.Therefore, during lower engine speeds flow interruption created by thewindage tray may not be needed. Furthermore, during low engine speedsthe windage tray may interfere with oil draining. For instance, oil mayimpinge on surfaces of windage trays, thereby interfering with oildraining operation. Specifically, the amount and/or speed of oilreturning to the oil pan may be reduced due to windage trayinterference. Furthermore, some windage trays may also create losses incrankcase ventilation systems.

U.S. Pat. No. 6,019,071 discloses a windage tray with an oil flow pathprovided in the windage tray with integrated oil squirters directing oiltowards the undersides of the engine pistons. However, the windage traydiscloses in U.S. Pat. No. 6,019,071 suffers from the abovementionedproblems of slow oil draining and crankcase ventilation losses.

Recognizing the problems described above and in an attempt to address atleast some of the problems the inventors developed a method foroperating an engine system. The method includes operating an engine toperform combustion, determining an engine speed and adjusting a flowprofile of a plurality of deflectors in a windage tray positioned in acrankcase based on the engine speed. In this way, the flow profile ofthe windage tray may be dynamically adjusted to alter flowcharacteristics in the crankcase over a wide range of engine speeds.Consequently, the functionality of the windage tray can be varied tosuit engine operating conditions, enabling the windage tray to reduceoil aeration during selected operating conditions while reducing windagetray flow interference during other operating conditions to increase oildraining, for instance.

In one example, the deflectors in the windage tray may be opened whenthe engine is operated below a threshold speed and closed when theengine is operated above the threshold speed. In this way, the windagetray acts to decrease crankcase turbulence around the lubricantreservoir, thereby decreasing oil aeration during high speed operation.Conversely, during lower speed engine operation the lubricant drainageinterference is mitigated by opening the deflectors in the windage tray,thereby increasing the lubrication system efficiency.

It should be understood that the summary above is provided to introducein simplified form a selection of concepts that are further described inthe detailed description. It is not meant to identify key or essentialfeatures of the claimed subject matter, the scope of which is defineduniquely by the claims that follow the detailed description.Furthermore, the claimed subject matter is not limited toimplementations that solve any disadvantages noted above or in any partof this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic depiction of an internal combustion engineincluding a windage tray with adjustable deflectors.

FIG. 2 shows an illustration of a cross-section of a first example of awindage tray with adjustable deflectors in a closed configuration.

FIG. 3 shows an illustration of a cross-section of the first example ofthe windage tray with the adjustable deflectors in an openconfiguration.

FIG. 4 shows a perspective view of another exemplary windage tray withadjustable deflectors.

FIG. 5 shows a method for operation of an engine system with anadjustable windage tray.

FIG. 6 shows another method for operation of an engine system with anadjustable windage tray.

FIG. 7 shows a timing diagram of an exemplary windage tray controlstrategy.

DETAILED DESCRIPTION

The following description relates to an engine system and method forvarying the flow profile of a windage tray based on engine speed,enabling the windage tray to act to interrupt crankcase turbulenceduring targeted conditions. The engine system includes a windage traywith adjustable deflectors (e.g., louvers) to achieve flow interferenceadaptability. The deflectors may be pivoted or otherwise moved toincrease and decrease the amount of crankcase gas passing through thewindage tray. In one example, the deflectors may be moved into openpositions during lower speed operation to increase lubricant draining.Continuing with such an example, during higher speed operation thedeflectors may be closed to reduce the likelihood of crankcaseturbulence causing lubricant aeration. As a result, engine lubricationis enhanced during both high and low speed engine operation, therebyincreasing engine reliability and longevity.

FIG. 1 shows a schematic depiction of an engine system with a windagetray. FIG. 2 shows an example of the engine system with the windage traywith deflectors in the windage tray in a closed position. FIG. 3 showsthe engine system and windage tray shown in FIG. 2 with the deflectorsin an open position. FIG. 4 shows a perspective view of anotherexemplary windage tray. FIGS. 5 and 6 show methods for operation ofengine systems with windage trays to vary flow patterns in the crankcaseand lubricant reservoir based on engine operating conditions. FIG. 7shows a timing diagram associated with a windage tray control strategywhich decreases lubricant aeration and increases lubricant draining in alubricant system.

Turning to FIG. 1, an engine 10 with an engine system 12 in a vehicle 14is schematically illustrated. Although, FIG. 1 provides a schematicdepiction of various engine and engine system, it will be appreciatedthat at least some of the components may have a different spatialpositions and greater structural complexity than the components shown inFIG. 1. The structural details of the components are discussed ingreater detail herein with regard to FIGS. 2-4.

An intake system 16 providing intake air to a combustion chamber 18, isalso depicted in FIG. 1. A piston 20 is positioned in the combustionchamber 18. The piston 20 is coupled to a crankshaft 22 via a mechanicalcomponent 24 (e.g., piston rod). The combustion chamber 18 is formed bya cylinder block 26 coupled to a cylinder head 28. Although, FIG. 1depicts the engine 10 with one combustion chamber. The engine 10 mayhave additional combustion chambers, in other examples. For instance,the engine 10 may include a plurality of combustion chambers which mayin some instances be positioned in banks.

The intake system 16 includes an intake conduit 30 and a throttle 32coupled to the intake conduit. The throttle 32 is configured to regulatethe amount of airflow provided to the combustion chamber 18. In thedepicted example, the intake conduit 30 feeds air to an intake manifold34. In turn, the intake manifold 34 directs air to an intake valve 36.However, in other examples, such as in a multi-cylinder engine intakerunners may branch off of the intake manifold and feed intake air toother intake valves.

The intake valve 36 may be actuated by an intake valve actuator 38.Likewise, an exhaust valve 40 may be actuated by an exhaust valveactuator 42. In one example, the intake valve actuator 38 and theexhaust valve actuator 42 may employ cams coupled to intake and exhaustcamshafts (not shown), respectively, to open/close the valves.Continuing with the cam driven valve actuator example, the intake andexhaust camshafts may be rotationally coupled to the crankshaft 22.Further in such an example, the valve actuators may utilize one or moreof cam profile switching (CPS), variable cam timing (VCT), variablevalve timing (VVT), and/or variable valve lift (VVL) systems to varyvalve operation. Thus, cam timing devices may be used to vary the valvetiming, if desired. It will therefore be appreciated that valve overlapmay occur. In another example, the intake and/or exhaust valveactuators, 38 and 42, may be controlled by electronic valve actuation.For example, the valve actuators, 38 and 42, may be electronic valveactuators controlled via electronic actuation. In yet another example,the engine 10 may alternatively include exhaust valves controlled viaelectric valve actuation and intake valves controlled via cam actuationincluding CPS and/or VCT systems or vice versa. In still otherembodiments, the intake and exhaust valves may be controlled by a commonvalve actuator or actuation system.

The engine 10 further includes a lubrication system 44 providinglubricant to engine components such as the piston 20, crankshaft 22,mechanical component 24, etc. The lubrication system 44 includes alubricant reservoir 46 that receiving lubricant from the lubricatedcomponents (e.g., pistons, crankshaft, piston rods, etc.). Thus, thelubricant reservoir 46 in the lubrication system 44 may be designed toreceive lubricant draining from the lubricated components such as thepistons 20, crankshaft 22, mechanical component 24, etc. For instance,the lubricant reservoir 46 may be positioned below the lubricatedcomponents to receive oil that has been sprayed or otherwise deliveredto the lubricated components. A lubricant pump 48 is positioned in thelubricant reservoir 46 in the illustrated example. However, in otherexamples, the lubricant pump 48 may be positioned external to thelubricant reservoir with a pick-up line extending into the reservoir.The lubricant pump 48 is configured to flow pressurized lubricant to aplurality of lubrication lines 50. The plurality of lubrication lines 50are schematically illustrated. However it will be appreciated that thelubrication lines may extend through different sections of the cylinderblock 26 and/or cylinder head 28 to provide lubricant to the piston 20,the crankshaft 22, the mechanical component 24, etc. The lubricationsystem 44 may further include nozzles designed to spray or otherwisedirect lubricant to the piston, crankshaft, etc., and are discussed ingreater detail herein with regard to FIGS. 2 and 3. The lubricationsystem 44 also includes valves that are designed to regulate theflowrate of the lubricant provided to the lubricated components,discussed in greater detail herein with regard to FIGS. 2 and 3.

The engine 10 may also include an engine cooling system (not shown). Theengine cooling system may include coolant jackets circulating coolantthrough the cylinder head and/or cylinder block as well as a heatexchanger (e.g., radiator) removing heat from the coolant.

A fuel delivery system 52 is also shown in FIG. 1. The fuel deliverysystem 52 provides pressurized fuel to a fuel injector 54. In theillustrated example, the fuel injector 54 is a direct fuel injectorcoupled to combustion chamber 18. Additionally or alternatively, thefuel delivery system 52 may also include a port fuel injector designedto inject fuel upstream of the combustion chamber 18 into the intakesystem 16. The fuel delivery system 52 includes a fuel tank 56 and afuel pump 58 designed flow pressurized fuel to downstream components. Afuel line 60 provides fluidic communication between the fuel pump 58 andthe fuel injector 54. The fuel delivery system 52 may includeconventional components such as a high pressure fuel pump, check valves,return lines, etc., to enable fuel to be provided to the injectors atdesired pressures.

An exhaust system 62 configured to manage exhaust gas from thecombustion chamber 18 is also included in the vehicle 14 depicted inFIG. 1. The exhaust system 62 includes the exhaust valve 40 designed toopen and close to allow and inhibit exhaust gas flow to downstreamcomponents from the combustion chamber. The exhaust system 62 alsoincludes an emission control device 64 coupled to an exhaust conduit 66downstream of an exhaust manifold 68. The emission control device 64 mayinclude filters, catalysts, absorbers, etc., for reducing tailpipeemissions. The engine 10 also includes an ignition system 70 includingan energy storage device 72 designed to provide energy to an ignitiondevice 74. Additionally or alternatively, the engine 10 may performcompression ignition.

The engine system 12 is designed to vary the flow pattern in thelubricant reservoir 46 and a crankcase 82. The engine system 12 includesa windage tray 84. The windage tray 84 includes adjustable deflectorsthat may be actively controlled to alter the amount of crankcase gasflowing through the windage tray. For instance, the deflectors may beopened to allow crankcase gas to flow through the windage tray duringlow engine speeds. Continuing with such an example, the deflectors maybe closed to inhibit crankcase gas from flowing through the windage trayduring high engine speeds. The deflectors are described in greaterdetail herein with regard to FIGS. 2-4. Further in one example, theengine system 12 may also include the lubricant reservoir 46, thelubricant pump 48, and/or the crankshaft 22.

During engine operation, the combustion chamber 18 typically undergoes afour stroke cycle including an intake stroke, compression stroke,expansion stroke, and exhaust stroke. During the intake stroke,generally, the exhaust valve closes and intake valve opens. Air isintroduced into the combustion chamber via the corresponding intakeconduit, and the piston moves to the bottom of the combustion chamber soas to increase the volume within the combustion chamber. The position atwhich the piston is near the bottom of the combustion chamber and at theend of its stroke (e.g., when the combustion chamber is at its largestvolume) is typically referred to by those of skill in the art as bottomdead center (BDC). During the compression stroke, the intake valve andthe exhaust valve are closed. The piston moves toward the cylinder headso as to compress the air within combustion chamber. The point at whichthe piston is at the end of its stroke and closest to the cylinder head(e.g., when the combustion chamber is at its smallest volume) istypically referred to by those of skill in the art as top dead center(TDC). In a process herein referred to as injection, fuel is introducedinto the combustion chamber. In a process herein referred to asignition, the injected fuel in the combustion chamber is ignited viacompression, resulting in combustion. However, in other examples,additionally or alternatively, spark from an ignition device may be usedto ignite the air fuel mixture in the combustion chamber. During theexpansion stroke, the expanding gases push the piston back to BDC. Acrankshaft converts this piston movement into a rotational torque of therotary shaft. During the exhaust stroke, in a traditional design,exhaust valve is opened to release the residual combusted air-fuelmixture to the corresponding exhaust passages and the piston returns toTDC.

FIG. 1 also shows a controller 100 in the vehicle 14. Specifically,controller 100 is shown in FIG. 1 as a conventional microcomputerincluding: microprocessor unit 102, input/output ports 104, read-onlymemory 106, random access memory 108, keep alive memory 110, and aconventional data bus. Controller 100 is configured to receive varioussignals from sensors coupled to the engine 10. The sensors may includeengine coolant temperature sensor 130, exhaust gas composition sensor132, exhaust gas airflow sensor 134, an intake airflow sensor 136,manifold pressure sensor 137, engine speed sensor 138, vibration sensor140, etc. Additionally, the controller 100 is also configured to receivethrottle position (TP) from a throttle position sensor 112 coupled to apedal 114 actuated by an operator 116.

Additionally, the controller 100 may be configured to trigger one ormore actuators and/or send commands to components. For instance, thecontroller 100 may trigger adjustment of the throttle 32, lubricationsystem 44, intake valve actuator 38, exhaust valve actuator 42, enginesystem 12, fuel delivery system 52, and/or the ignition system 70.Specifically, the controller 100 may be configured to send signals tothe windage tray 84 to adjust the position of deflectors (e.g., louvers)in the windage tray. The controller 100 may also be configured to sendcontrol signals to the lubrication system 44 to control the amount oflubricant delivered to targeted lubricated components. Furthermore, thecontroller 100 may be configured to send control signals to the fuelpump 58 and the fuel injector 54 to control the amount and timing offuel injection provided to the combustion chamber 18. The controller 100may also send control signals to the throttle 32 to vary engine speed.

Therefore, the controller 100 receives signals from the various sensorsand employs the various actuators to adjust engine operation based onthe received signals and instructions stored in memory (e.g.,non-transitory memory) of the controller. Thus, it will be appreciatedthat the controller 100 may send and receive signals from the enginesystem 12. For example, adjusting deflectors in the windage tray mayinclude adjusting deflector actuators to adjust the deflectors in thewindage tray. In yet another example, adjusting the degree of opening ofdeflectors in the windage tray, may be empirically determined and storedin predetermined lookup tables and/or functions. For example, one tablemay correspond to determining an amount of deflector opening in thewindage tray when the engine is operating within a first speed range andanother table may correspond to determining an amount deflector openingin the windage tray when the engine is operating within a second speedrange that is less than the first speed range. The tables may be indexedto engine operating conditions such as engine speed, engine load, amongother engine operating conditions. Furthermore, the tables may output anamount of fuel to inject via the fuel injectors to the combustionchamber at each cylinder cycle. Thus, it will be appreciated that thecontroller 100 may be configured to implement the methods, controlstrategies, etc., described herein with regard to an engine systemincluding a windage tray.

FIG. 2 shows a first example of an internal combustion engine 200 andengine system 202 in cross-section. A z-axis and x-axis are provided inFIG. 2 as well as FIG. 3, for reference. FIG. 4 also shows a y-axisalong with the z-axis and the x-axis for reference. In one example, thez-axis may be parallel to a gravitational axis. The x-axis may be alateral axis, in one example. Furthermore, the y-axis may be alongitudinal axis, in one instance. However in other examples, other,x-axis, y-axis, and z-axis orientations have been contemplated. It willbe appreciated that the engine 200 and the engine system 202, shown inFIG. 2, are examples of the engine 10 and the engine system 12, shown inFIG. 1. Therefore, features in the engine 10 and engine system 12 shownin FIG. 1 may be included in the engine 200 and engine system 202, shownin FIG. 2, or vice versa.

FIG. 2 shows the engine 200 including a cylinder block 204 coupled to acylinder head 206 forming a combustion chamber 208. Although only onecylinder is depicted in FIG. 2, it will be appreciated that the engine200 may include additional combustion chambers. In such an example, awindage tray 210 included in the engine system 202 may extend underneathpistons and associated piston rods, for instance.

Additionally, an exhaust valve 212 and an intake valve 214 are showncoupled to the combustion chamber 208. The intake valve 214 includes anintake valve stem 215 and the exhaust valve 212 includes an exhaustvalve stem 217. Correspondingly, intake conduit 216 and exhaust conduit218 providing fluidic communication between upstream intake systemcomponents and downstream exhaust system components, are also depictedin FIG. 2.

A piston 220 is positioned within the combustion chamber 208. The piston220 include piston rings 222 designed to seal the combustion chamber208. A piston rod 224 is attached to the piston 220 and a crankshaft226.

A direct fuel injector 228 is also shown coupled to the combustionchamber 208. However, a port fuel injector may additionally oralternatively be included in the engine. A lubrication system 230 isalso shown in FIG. 2. The lubrication system 230 includes a lubricantpump 232 designed to circulate lubricant through lubricant lines in thelubrication system. Furthermore, the lubricant pump 232 may be drivenvia rotational energy extracted from the crankshaft, in one example.However, in other examples, the lubricant pump 232, may be an electricalpump. Suitable pumps such as a gear pump, trochoid pump, vane pump,etc., have been contemplated. The lubricant pump 232 includes a pick-upline 234 with an inlet 236 directing lubricant 283 from a lubricantreservoir 238 into the pump. The lubricant pump 232 also includes anoutlet 240 in fluidic communication with a lubricant line 242. Alubricant valve 244 coupled to the lubricant line 242. The lubricantvalve 244 is configured to vary the amount of lubricant flowing throughthe lubricant line 242. For instance, the lubricant valve 244 may befully opened, fully closed, and/or may have varying degrees of openingand closure. The lubricant valve 244 as well as other lubricant valvesdescribed herein may be an on/off electrically actuated solenoid valve,an on/off pneumatically actuated solenoid valve, an on/off electricallyactuated piezoelectric stack valve, an electrically actuatedproportioning valve, or a pneumatically actuated proportioning valve. Anozzle 246 is coupled to an end of the lubricant line 242. The nozzle246 is designed to direct lubricant spray towards an underside 248 ofthe piston 220 to lubricate said piston. It will be appreciated that thelubrication system 230 may also include additional lubricant linesdirecting lubricant towards other lubricated components such as thecrankshaft 226, the intake valve stem 217, the exhaust valve stem 215,etc.

The lubricant reservoir 238 is also included in the lubrication system230 shown in FIG. 2. The lubricant reservoir 238 includes a housing 250defining an interior section 252 of the lubricant reservoir 238 storinglubricant (e.g., oil).

A crankcase 254 is also shown in FIG. 2. The crankcase 254 houses thecrankshaft 226. A crankcase housing 256 may for at least a portion ofthe boundary of the crankcase 254. Further in one example, the cylinderblock 204 may also form a boundary of the crankcase 254.

FIG. 2 also shows a crankcase ventilation system 258. The crankcaseventilation system 258 includes a ventilation conduit 260 extendingthrough the crankcase housing 256 into the crankcase 254. Thus, a firstend 262 of the ventilation conduit 260 opens into the crankcase. Theventilation conduit 260 extend between the crankcase 254 and the intakeconduit 216. A crankcase ventilation valve 264 is also coupled to theventilation conduit 260. The crankcase ventilation valve 264 may beopened when there is a sufficient vacuum generated in the intake conduit216 and crankcase ventilation flow is desired. The crankcase ventilationvalve 264 may be controlled via pressure gradients between the intakesystem and crankcase. The crankcase ventilation valve and oil separatorpressure drop requirements may be determined based on enginearchitecture and operating regimes, in one example. It will beappreciated that the controller 100 may send and receive signals fromthe valves, sensors, etc., shown in FIGS. 2 and 3. For instance, thecontroller 100 may adjust operation of the crankcase ventilation valve264, the lubricant pump 232, windage tray 210, lubricant valve 244, etc.

The engine system 202 includes the windage tray 210. The engine system202 may also include the lubricant reservoir 238, the lubricant pump232, and/or the crankshaft 226. The windage tray 210 is positioned below(e.g., vertically below) the crankshaft and above (e.g., verticallyabove) the lubricant pump 232. The windage tray 210 also shownpositioned in the lubricant reservoir 238. It will be appreciated thatin other examples the windage tray 210 may extend into the crankcase254. Thus, in some examples, the windage tray 210 may be attached (e.g.,fixedly attached) to the lubricant reservoir housing 250 and/or thecrankcase housing 256.

The windage tray 210 is shown including deflectors 266. The deflectors266 are positioned in inclined sections 268 of the base 270 of the tray.However, other deflector positions have been contemplated. In the closedpositioned the deflectors 266 may be aligned with upper surfaces 274 ofthe inclined sections 268, to substantially reduce (e.g., inhibit)crankcase gas flow through the windage tray. The deflectors 266 aremoveably coupled (e.g., pivotally coupled) to the base 270.Specifically, the deflectors 266 are designed to pivot about deflectorpivots 272. However, deflectors with alternate adjustment mechanismshave been contemplated.

FIG. 2 also shows a fixed deflector 276 and an opening 278 in thewindage tray 210. The opening 278 enables lubricant to drain and passthrough the windage tray and into the lubricant reservoir 238. In thisway, lubricant build up on the windage tray may be avoided, therebyreducing interference between the lubrication system 230 and the windagetray 210. Consequently, lubrication system 230 efficiency may beincreased.

Actuators 280 configured to adjust the positions of the deflectors areshown coupled to the deflectors. It will be appreciated that in otherexamples, a single actuator may actuate all of the deflectors or theactuators may actuate more than one deflector. In one example, theactuators 280 may be hydraulic actuators controlling the position of thedeflectors 266 (e.g., louvers) via hydraulics. However, other suitableactuators have been contemplated.

Arrows 282 indicate the general direction of crankcase gas flow aroundthe windage tray 210. Thus, when the deflectors 266 are in a closedposition crankcase gas is substantially inhibited from flowing throughthe interior of the windage tray 210. However, in other examples whenthe deflectors 266 are in the closed position crankcase gas flow throughthe windage tray may be substantially reduced. As illustrated in FIG. 2,crankcase gas is direct towards the periphery of the windage tray nearthe lubricant reservoir housing 250. As a result, crankcase gasinterference with lubricant 283 (e.g., oil) in the lubricant reservoir238 is reduced, thereby reducing lubricant aeration. It will beappreciated that the gas flow pattern in around the windage tray 210 hasgreater complexity than is illustrated in FIG. 2.

It will be appreciated that the windage tray 210 (e.g., actuators 280),lubricant valve 244, crankcase ventilation valve 264, lubricant pump232, and/or direct fuel injector 228 may receive control signals fromthe controller 100, shown in FIG. 1, and may also send signals to thecontroller. An engine speed sensor 284 coupled to the crankshaft 226 isalso shown in FIG. 2. It will be appreciated that the engine speedsensor 284 may send signals to the controller 100, shown in FIG. 1.

FIG. 2 shows the deflectors 266 in a closed position while FIG. 3 showsthe engine system 202 with the windage tray 210 with the deflectors inan open position. It will be appreciated that the actuators 280 may becommanded to place the deflectors 266 in the open position.Specifically, as shown in FIG. 3 the deflectors 266 are pivoted aboutthe deflector pivots 272 such that the deflectors extend away from thebase 270 of the windage tray 210. When the deflectors 266 are moved inthis manner openings 300 in the windage tray 210 are uncovered. However,other deflector adjustment kinematics have been contemplated. When theopenings 300 are uncovered crankcase gas can flow through the windagetray 210. Thus, when the deflectors 266 are moved into the open positionfrom the closed position the flowrate of crankcase gas through thewindage tray is increased. Conversely, when the deflectors 266 are movedfrom the open position to the closed position the flowrate of crankcasegas through the windage tray is reduced. Arrows 302 depict the generaldirection of gas flow through the openings 300. However, it will beappreciated that the gas flow pattern in the crankcase and through theopenings has greater complexity than is illustrated.

In a fully open configuration the deflectors 266 may be arrangedperpendicular to the base 270 of the windage tray 210. However, otherorientations between the fully opened deflectors and the base of thewindage tray have been contemplated. Conversely, in the closed positionthe deflectors 266 may be parallel to the base 270 of the windage tray.However, other orientations between the closed deflectors and the basehas been envisioned such as 2°, 5°, 10°, etc., angles formed between thedeflectors and the base. In the open position the deflectors 266 allowgas to flow through the windage tray 210 from the crankcase 254 to thelubricant reservoir 238.

Lubricant may also flow through the openings 300 when the deflectors 266are opened to increase lubricant draining. Lubricant also drains throughthe opening 278 next to the fixed deflector 276. Arrow 304 indicates thegenerate path of lubricant flow through the openings 278. Consequently,lubricant can more efficiently drain into the lubricant reservoir 238.

It will be appreciated that the deflectors 266 in the windage tray 210may be placed in the open configuration shown in FIG. 3 when the engineis operating above a threshold speed (e.g., 5,000 RPM, 5,500 RPM, 6,000RPM, etc.,) in one instance. Conversely, the deflectors 266 in thewindage tray 210 may be placed in the closed configuration shown in FIG.2 when the engine is operating below the threshold speed.

In another example, the deflectors 266 in the windage tray 210 may beplaced in the open configuration, shown in FIG. 3, when the engine speedis increasing. Thus, in such an example, the deflectors may be placed inthe closed configuration, shown in FIG. 2, when the engine speed isdecreasing. Control strategies for the deflectors in the windage trayare discussed in greater detail herein with regard to FIGS. 5, 6, and 7.

FIG. 3 again shows the engine 200, engine system 202, cylinder block204, cylinder head 206, combustion chamber 208, piston 220, piston rod224, crankshaft 226, crankcase housing 256, and engine speed sensor 284.The intake valve 214, the exhaust valve 212, intake conduit 216, exhaustconduit 218, direct fuel injector 228, lubricant pump 232, lubricantvalve 244, lubricant line 242, nozzle 246, lubricant reservoir 238,crankcase ventilation system 258, ventilation conduit 260, and crankcaseventilation valve 264 are also shown in FIG. 3.

FIG. 4 shows a perspective view of an exemplary windage tray 400. Thewindage tray 400 shown in FIG. 4 is an example of the windage tray 210,shown in FIGS. 2 and 3. Therefore, the windage tray 400 may be includedin the engine system 202, shown in FIGS. 2 and 3. Furthermore, thewindage tray 400 shown in FIG. 4 may receive signals from the controller100, shown in FIG. 1, to adjust operation thereof.

The windage tray 400 includes a first end 402, a second end 404, a firstside 406, and a second side 408. The windage tray 400 also includesflanges 410 configured to attach to a section of a crankcase housing,cylinder block, lubricant reservoir housing, etc.

The windage tray 400 includes different sets 412 of deflectors, each sethaving a plurality of deflectors 414. As shown, the plurality ofdeflectors included in each set overlap with one another, in the closedposition shown in FIG. 4. However, in other examples the deflectors ineach set may be spaced away from one another. Each set of deflectors ispositioned at different longitudinal positions along the windage tray400. However, in other examples, the windage tray may include deflectorsextending longitudinally down the length of the tray. It will beappreciated that numerous deflector profiles that enable the flowprofile of the windage tray to be actively adjusted have beencontemplated. It will also be appreciated that the second side 408 ofthe windage tray 210 may include sets of deflectors similar to the firstside 406 of the windage tray.

The deflectors 414 shown in FIG. 4 are depicted as louvers plates. Eachof the louver plates have a similar geometry in the illustrated example.However, in other examples the profile of the louver plates may varywithin the sets of the louver plates and/or from set to set, forexample. Specifically, in the illustrated example, the louver plateshave a length 416 that is greater than their width 418. Additionally, atop surface 420 of the deflectors is also illustrated as substantiallyplanar. However, other louver plate geometries have been contemplated.For instance, the louver plates may have a curved (e.g., convex orconcave) upper surface and/or may taper in a longitudinal or a lateraldirection.

Arrows 422 indicate the direction of deflector movement when thedeflectors 414 are shifted from the closed position shown in FIG. 4 toan open position. In one example, the sets 412 of the deflectors may becorrespondingly adjusted. That is to say that each of the deflectors 414may be opened/closed by corresponding amounts. However in otherexamples, the sets 412 of the deflectors may be independently adjusted.For instance, a first set of deflectors may be opened while another setof deflectors may be closed or the degree of opening or closure indifferent sets of deflectors may vary between the sets of deflectorand/or within specific deflectors in the sets. For instance, a first setof deflectors may be opened while another set of deflectors may beclosed. The variations in deflector opening may be determined based onengine operating conditions. For instance, the deflectors may be closedwhen the engine is operating above a threshold speed and may be openedwhen the engine is operating below the threshold speed. In otherexamples, the degree of opening of the deflectors may decrease as theengine speed increases. Correspondingly, the degree of opening of thedeflectors may increase as the engine speed decreases.

FIGS. 2-4 show example configurations with relative positioning of thevarious components. If shown directly contacting each other, or directlycoupled, then such elements may be referred to as directly contacting ordirectly coupled, respectively, at least in one example. Similarly,elements shown contiguous or adjacent to one another may be contiguousor adjacent to each other, respectively, at least in one example. As anexample, components laying in face-sharing contact with each other maybe referred to as in face-sharing contact. As another example, elementspositioned apart from each other with only a space there-between and noother components may be referred to as such, in at least one example. Asyet another example, elements shown above/below one another, at oppositesides to one another, or to the left/right of one another may bereferred to as such, relative to one another. Further, as shown in thefigures, a topmost element or point of element may be referred to as a“top” of the component and a bottommost element or point of the elementmay be referred to as a “bottom” of the component, in at least oneexample. As used herein, top/bottom, upper/lower, above/below, may berelative to a vertical axis of the figures and used to describepositioning of elements of the figures relative to one another. As such,elements shown above other elements are positioned vertically above theother elements, in one example. As yet another example, shapes of theelements depicted within the figures may be referred to as having thoseshapes (e.g., such as being circular, straight, planar, curved, rounded,chamfered, angled, or the like). Further, elements shown intersectingone another may be referred to as intersecting elements or intersectingone another, in at least one example. Further still, an element shownwithin another element or shown outside of another element may bereferred as such, in one example.

FIG. 5 shows a method 500 for operation of an engine system with awindage tray including adjustable deflectors. Method 500 as well as theother methods described herein may be implemented by engines and pistonheating systems described above with regard to FIGS. 1-4 or may beimplemented by other suitable engines and piston heating systems, inother examples. Instructions for carrying out the method 500 and theother methods described herein may be executed by a controller based oninstructions stored in memory (e.g., non-transitory) executable by thecontroller and in conjunction with signals received from sensors of inthe engine and corresponding systems, such as the sensors describedabove with reference to FIGS. 1-4. The controller may employ engineactuators of the engine systems to adjust engine operation, according tothe methods described below.

At 502 the method includes operating the engine with an engine speed. Itwill be appreciated that the engine speed may be adjusted based onsignals from a pedal position sensor or other suitable accelerationrequest sensor. Moreover, it will be appreciated that operating theengine with an engine speed including operating the engine to performcombustion.

At 504 the method includes determining engine operating conditions. Theengine operating conditions may include engine speed, engine load,intake flowrate, engine temperature, exhaust gas flowrate, exhaust gascomposition, engine vibration, crankcase ventilation flowrate, etc. Theengine operating conditions may be ascertained from signals sent fromvarious sensors in the engine and/or determined (e.g., calculated) basedon signals from the sensors.

At 506 the method includes determining if the engine is operating abovea threshold speed. The threshold speed may be 4,000 RPM, 4,500 RPM, or5,000 RPM, in some examples. In another example, oil pressure may be acriterion that could be used to determine the flow return rate to theoil pump and windage tray operating regime.

If it is determined that the engine is not operating above the thresholdspeed (NO at 506) the method proceeds to 508. At 508 the method includesmaintaining the degree of opening of deflectors in the windage tray. Forinstance, the deflectors may be maintained in a fully opened or apartially opened position. Thus, the windage tray may be operated withdeflectors in an open position. In this way, crankcase gas may flowthrough the windage tray and lubricant draining through the windage traymay be increased. In other examples, the deflectors may be moved into afully opened or a partially opened position or the degree of opening ofthe deflectors may be increased at 508.

On the other hand, if it is determined that the engine is operatingabove the threshold speed (YES at 506) the method advances to 510. At510 the method includes decreasing a degree of opening of thedeflectors. In this way, a flowrate of crankcase gas through the windagetray is decreased. In one example, decreasing a degree of opening of thedeflectors may include placing the deflectors in a closed position.Thus, the windage tray may be operated with the deflectors in a closedposition. As previously discussed, in the closed position crankcase gasthrough openings in the windage tray may be substantially inhibited.However in other examples, decreasing a degree of opening of thedeflectors may include placing the deflectors in a partially closedposition. Furthermore, as previously discussed adjusting a degree ofopening or closing of the deflectors may include pivoting the deflectorsat one end about a pivot.

At 512 the method includes determining if the engine is operating belowthe threshold speed. It will be appreciated that the operatingconditions may be again determined prior to or during step 512. If it isdetermined that the engine is not operating below the threshold speed(NO at 512) the method proceeds to 514. At 514 the method includesmaintaining the positions of the deflectors. For instance, thedeflectors may be maintained in a closed position.

However, if it is determined that the engine is operating below thethreshold speed (YES at 512) the method advances to 516. At 516 themethod includes increasing a degree of opening of the deflectors.Increasing a degree of opening of the deflectors may include moving thedeflectors into a partially opened or fully opened position, in oneexample.

It will be appreciated that steps 506, 510, 512, and 516 may be includedin a more general step of adjusting a flow profile of the plurality ofdeflectors in the windage tray based on engine speed. In this way, thewindage tray may be adapted to suit the current engine operatingconditions.

At 518 the method includes determining if there is an increase incrankcase ventilation. The position of a crankcase ventilation valveand/or intake manifold pressure may be used to determine if there is anincrease in crankcase ventilation. In other examples, it may bedetermined if the flowrate of crankcase ventilation gas surpasses athreshold value.

If it is determined that there is not an increase in crankcaseventilation (NO at 518) the method proceeds to 520. At 520 the methodincludes maintaining the current engine speed threshold. However, if itis determined that there is an increase in crankcase ventilation (YES at518) the method proceeds to 522 where the method includes decreasing theengine speed threshold. In this way, the engine speed threshold may bedecreased when the crankcase ventilation system causes increasedturbulence in the crankcase and lubricant reservoir. Consequently, thedeflectors in the windage tray may be closed at lower engine speeds todecrease lubricant aeration.

FIG. 6 shows another method 600 for operation of an engine system with awindage tray having adjustable deflectors. As discussed above, themethod may be implemented by the engines and engine systems describedabove with regard to FIGS. 1-4 or may be implemented by other suitableengines and engine systems.

At 602 the method includes determining engine operating conditions. Theoperating conditions may include engine speed, engine load, intakeflowrate, engine temperature, exhaust gas flowrate, exhaust gascomposition, engine vibration, crankcase ventilation flowrate, etc. Itwill be appreciated that the engine may be operated according to theaforementioned operating conditions.

At 604 the method includes determining if there is an increase in enginespeed. If there is an increase in engine speed (YES at 604) the methodadvances to 606. At 606 the method includes decreasing a degree ofopening of deflectors in a windage tray. For instance, the deflectors inthe windage tray may be placed in a closed position or a partiallyclosed position. However, if there is not an increase in engine speed(NO at 604) the method proceeds to 608. At 608 the method includesdetermining if there is a decrease in engine speed. If there is adecrease in engine speed (YES at 608) the method proceeds to 610. At 610the method includes increasing a degree of opening of the deflectors inthe windage tray. On the other hand, if there is not a decrease inengine speed (NO at 608) the method moves to 612. At 612 the methodincludes maintaining the degree of opening of the deflectors in thewindage tray. It will be appreciated that in other examples, steps 604and 608 may include determining if the engine is operating above athreshold speed or below a threshold speed, respectively.

At 614 the method includes determining if engine vibration is greaterthan a threshold value. If the engine vibration is greater than thethreshold value (YES at 614) the method moves to 616 where the methodincludes decreasing a degree of opening of the deflectors in the windagetray. Therefore it will be appreciated that vibration may be a catalystof lubricant aeration therefore the windage tray contour may beresponsively adjusted based on changes in engine vibration. In this way,the deflectors in the windage tray may be closed during periods ofelevated vibration to reduce lubricant aeration. If the engine vibrationis not greater than the threshold value (NO at 614) the method moves to618 where the method includes maintaining the position of the deflectorsin the windage tray. Method 600 enables the flow profile of the windagetray to be adjusted to decrease lubricant aeration as the engine speedincreases and to increase lubricant draining as the engine speeddecreases.

Now turning to FIG. 7, graphs 700 depict example engine system controlsignals in conjunction with engine speed and crankcase ventilationflowrate plots, such as described in FIGS. 1-6. The example of FIG. 7 isdrawn substantially to scale, even though each and every point is notlabeled with numerical values. As such, relative differences in timingscan be estimated by the drawing dimensions. However, other relativetimings may be used, if desired. Furthermore, each of the curves andplots time is represented on the x axis. It will also be appreciatedthat the plots in FIG. 7 are exemplary in nature and that, in otherexamples, the timing of the control signals, the threshold values, etc.,may vary.

Continuing with FIG. 7, curve 702 depicts the engine speed (along the yaxis). Signal 704 indicates a control signal sent to the windage traywith the adjustable deflectors. Curve 706 depicts the flowrate ofcrankcase gas into the intake system. The control signal 704 sent to thewindage tray is shows including two values (i.e., open and close).However, it will be appreciated that more finite adjustments arepossible such as stepwise or continuous adjustment of the deflectors toplace the deflectors in different partially opened positions. Forexample, the deflectors may have a plurality of position that havedifferent degrees of opening. Thus, each of the different deflectorpositions allow a different amount of crankcase gas flow through thewindage tray. In this way, the degree of deflector opening/closing maybe fine-tuned based on engine operating conditions.

At t1, the engine speeds surpasses a threshold engine speed 708. Thethreshold engine speed may be ascertained using the previously discussedtechniques. Responsive to the engine speed surpassing the engine speedthreshold the control signal 704 sent to the windage tray is changed to“open”. Consequently, the deflectors in the windage tray are opened toallow crankcase gas to flow therethrough as well as allow lubricant todrain through the windage tray.

At t2, the engine speed falls below the threshold engine speed 708.Responsive to the engine speed falling below the threshold engine speed708 the control signal 704 sent to the windage tray is changed to“close” to reduce (e.g., prevent) crankcase gas from flowing throughopenings in the windage tray. Consequently, the windage tray reducesflow interference between crankcase gas and lubricant in the lubricantreservoir when in the closed configuration, thereby reducing lubricantaeration.

At t3, the crankcase ventilation flowrate surpasses a threshold value710. When the crankcase ventilation flowrate surpasses the thresholdvalue 710, the threshold engine speed 708 is responsively decreased. Thecontrol signal 704 sent to the windage tray is changed to “open”responsive to the crankcase ventilation flowrate surpassing thethreshold value. The control strategy shown in FIG. 7 enables the flowprofile of the windage tray to be altered based on engine speed andcrankcase ventilation flow to enable the windage tray to providedifferent functions (e.g., oil aeration reduction and increased oildraining) that suit different engine conditions. Consequently, theefficiency of the lubrication system is increased.

The engine systems and methods described herein have the technicaleffect of decreasing lubricant aeration during high engine speeds andincreasing lubricant draining during lower engine speeds. As a results,lubrication system efficiency is increased across a wide range of engineoperating conditions.

The invention will further be described in the following paragraphs. Inone aspect, a method for operating an engine system is provided, themethod including operating an engine to perform combustion operation,determining an engine speed, and adjusting a flow profile of a pluralityof deflectors in a windage tray positioned in a crankcase based on theengine speed.

In another aspect an engine system is provided that includes a lubricantreservoir receiving lubricant from lubricated components, a lubricantpump positioned in the lubricant reservoir, a crankshaft positioned in acrankcase vertically above the lubricant reservoir and receivingrotational input from a piston rod, a windage tray positioned verticallybetween the lubricant pump and the crankshaft, the windage trayincluding a plurality of deflectors extending longitudinally along thewindage tray, and code stored in memory executable by a processor toincrease a degree of opening of the plurality of deflectors in responseto a decrease in engine speed.

In another aspect, a method for operating an engine system is provided,the method includes operating an engine with an engine speed is greaterthan a threshold value, and in response to operating the engine with theengine speed greater than a threshold value, adjusting a position offlow deflectors in a windage tray to decrease the flowrate of crankcasegas through openings in the windage tray.

In any of the aspects herein or combinations of the aspects, adjusting aflow profile of deflectors in the windage tray may include increasing adegree of opening of the deflectors when an engine speed is less than athreshold value and decreasing a degree of opening of the deflectorswhen the engine speed is greater than the threshold value.

In any of the aspects herein or combinations of the aspects, the methodmay further include adjusting the threshold value based on a flowrate ofcrankcase gas into an intake system through a crankcase ventilationsystem.

In any of the aspects herein or combinations of the aspects, adjustingthe threshold value may include decreasing the threshold value inresponse to an increase in a flowrate of crankcase gas into the intakesystem through the crankcase ventilation system.

In any of the aspects herein or combinations of the aspects, the methodmay further include adjusting a flow profile of the plurality ofdeflectors based on engine vibration.

In any of the aspects herein or combinations of the aspects, adjustingthe deflectors may include for each of the deflectors, rotating thedeflector at one end about a pivot.

In any of the aspects herein or combinations of the aspects, theplurality of deflectors may be louver plates.

In any of the aspects herein or combinations of the aspects, the louverplates may have a length greater than a width.

In any of the aspects herein or combinations of the aspects, theplurality of deflectors may pivot about pivots during the increase inthe degree of opening of the plurality of deflectors.

In any of the aspects herein or combinations of the aspects, the enginesystem may further include code stored in memory executable by theprocessor to decrease a degree of opening of the plurality of deflectorsin response to an increase in engine speed.

In any of the aspects herein or combinations of the aspects, theincrease in engine speed may include an increase in engine speed above athreshold value.

In any of the aspects herein or combinations of the aspects, the enginesystem may further include code stored in memory executable by theprocessor to adjust the threshold value based on a flowrate of crankcasegas into the intake system through a crankcase ventilation system.

In any of the aspects herein or combinations of the aspects, adjustingthe threshold value may include increasing the threshold value inresponse to a decrease in a flowrate of crankcase gas into the intakesystem through the crankcase ventilation system or decreasing thethreshold value in response to an increase in the flowrate of crankcasegas into the intake system through the crankcase ventilation system.

In any of the aspects herein or combinations of the aspects, the enginesystem may further include code stored in memory executable by theprocessor to increase a degree of opening of the plurality of deflectorsbased on engine vibration.

In any of the aspects herein or combinations of the aspects, the methodmay include operating the engine with an engine speed less than thethreshold value, and in response to operating the engine with the enginespeed less than the threshold value, adjusting a position of a pluralityof deflectors in a windage tray to increase the flowrate of crankcasegas through openings in the windage tray.

In any of the aspects herein or combinations of the aspects, the methodmay further include adjusting the threshold value based on a flowrate ofcrankcase gas into the intake system through a crankcase ventilationsystem.

In any of the aspects herein or combinations of the aspects, adjustingthe threshold value may include at least one of increasing the thresholdvalue in response to a decrease in a flowrate of crankcase gas into anintake system through the crankcase ventilation system and decreasingthe threshold value in response to an increase in the flowrate ofcrankcase gas into the intake system through the crankcase ventilationsystem.

In any of the aspects herein or combinations of the aspects, adjustingthe position of the plurality of deflectors may include for each of thedeflectors, rotating the deflector at one end about a deflector pivot.

Note that the example control and estimation routines included hereincan be used with various engine and/or vehicle system configurations.The control methods and routines disclosed herein may be stored asexecutable instructions in non-transitory memory and may be carried outby the control system including the controller in combination with thevarious sensors, actuators, and other engine hardware. The specificroutines described herein may represent one or more of any number ofprocessing strategies such as event-driven, interrupt-driven,multi-tasking, multi-threading, and the like. As such, various actions,operations, and/or functions illustrated may be performed in thesequence illustrated, in parallel, or in some cases omitted. Likewise,the order of processing is not necessarily required to achieve thefeatures and advantages of the example embodiments described herein, butis provided for ease of illustration and description. One or more of theillustrated actions, operations and/or functions may be repeatedlyperformed depending on the particular strategy being used. Further, thedescribed actions, operations and/or functions may graphically representcode to be programmed into non-transitory memory of the computerreadable storage medium in the engine control system, where thedescribed actions are carried out by executing the instructions in asystem including the various engine hardware components in combinationwith the electronic controller.

It will be appreciated that the configurations and routines disclosedherein are exemplary in nature, and that these specific embodiments arenot to be considered in a limiting sense, because numerous variationsare possible. For example, the above technology can be applied to V-6,I-4, I-6, V-12, opposed 4, and other engine types. The subject matter ofthe present disclosure includes all novel and non-obvious combinationsand sub-combinations of the various systems and configurations, andother features, functions, and/or properties disclosed herein.

The following claims particularly point out certain combinations andsub-combinations regarded as novel and non-obvious. These claims mayrefer to “an” element or “a first” element or the equivalent thereof.Such claims should be understood to include incorporation of one or moresuch elements, neither requiring nor excluding two or more suchelements. Other combinations and sub-combinations of the disclosedfeatures, functions, elements, and/or properties may be claimed throughamendment of the present claims or through presentation of new claims inthis or a related application. Such claims, whether broader, narrower,equal, or different in scope to the original claims, also are regardedas included within the subject matter of the present disclosure.

1. A method for operating an engine system comprising: operating anengine to perform combustion; determining an engine speed; and adjustinga flow profile of a plurality of deflectors in a windage tray positionedin a crankcase based on the engine speed.
 2. The method of claim 1,where adjusting a flow profile of deflectors in the windage trayincludes increasing a degree of opening of the deflectors when an enginespeed is less than a threshold value and decreasing a degree of openingof the deflectors when the engine speed is greater than the thresholdvalue.
 3. The method of claim 2, further comprising adjusting thethreshold value based on a flowrate of crankcase gas into an intakesystem through a crankcase ventilation system.
 4. The method of claim 3,where adjusting the threshold value includes decreasing the thresholdvalue in response to an increase in a flowrate of crankcase gas into theintake system through the crankcase ventilation system.
 5. The method ofclaim 1, further comprising adjusting a flow profile of the plurality ofdeflectors based on engine vibration.
 6. The method of claim 1, whereadjusting the deflectors includes for each of the deflectors, rotatingthe deflector at one end about a pivot.
 7. An engine system comprising:a lubricant reservoir receiving lubricant from lubricated components; alubricant pump positioned in the lubricant reservoir; a crankshaftpositioned in a crankcase vertically above the lubricant reservoir andreceiving rotational input from a piston rod; a windage tray positionedvertically between the lubricant pump and the crankshaft, the windagetray including a plurality of deflectors extending longitudinally alongthe windage tray; and code stored in memory executable by a processorto: increase a degree of opening of the plurality of deflectors inresponse to a decrease in engine speed.
 8. The engine system of claim 7,where the plurality of deflectors are louver plates.
 9. The enginesystem of claim 8, where the louver plates have a length greater than awidth.
 10. The engine system of claim 7, where the plurality ofdeflectors pivot about pivots during the increase in the degree ofopening of the plurality of deflectors.
 11. The engine system of claim7, further comprising code stored in memory executable by the processorto decrease a degree of opening of the plurality of deflectors inresponse to an increase in engine speed.
 12. The engine system of claim11, where the increase in engine speed includes an increase in enginespeed above a threshold value.
 13. The engine system of claim 7, furthercomprising code stored in memory executable by the processor to adjustthe threshold value based on a flowrate of crankcase gas into the intakesystem through a crankcase ventilation system.
 14. The engine system ofclaim 7, where adjusting the threshold value includes increasing thethreshold value in response to a decrease in a flowrate of crankcase gasinto the intake system through the crankcase ventilation system ordecreasing the threshold value in response to an increase in theflowrate of crankcase gas into the intake system through the crankcaseventilation system.
 15. The engine system of claim 7, further comprisingcode stored in memory executable by the processor to increase a degreeof opening of the plurality of deflectors based on engine vibration. 16.A method for operating an engine system comprising: operating an enginewith an engine speed is greater than a threshold value; and in responseto operating the engine with the engine speed greater than a thresholdvalue, adjusting a position of flow deflectors in a windage tray todecrease the flowrate of crankcase gas through openings in the windagetray.
 17. The method of claim 16, further comprising: operating theengine with an engine speed less than the threshold value; and inresponse to operating the engine with the engine speed less than thethreshold value, adjusting a position of a plurality of deflectors in awindage tray to increase the flowrate of crankcase gas through openingsin the windage tray.
 18. The method of claim 16, further comprisingadjusting the threshold value based on a flowrate of crankcase gas intothe intake system through a crankcase ventilation system.
 19. The methodof claim 18, where adjusting the threshold value includes at least oneof increasing the threshold value in response to a decrease in aflowrate of crankcase gas into an intake system through the crankcaseventilation system and decreasing the threshold value in response to anincrease in the flowrate of crankcase gas into the intake system throughthe crankcase ventilation system.
 20. The method of claim 16, whereadjusting the position of the plurality of deflectors includes for eachof the deflectors, rotating the deflector at one end about a deflectorpivot.